Pakistan MCQs

The henry is the SI unit of inductance.
Inductance relates induced voltage to rate of current change.

Reactance depends on frequency and energy storage elements.
It contributes to impedance without directly dissipating average power.

Impedance combines resistance and reactance.
It is represented as a complex quantity in AC analysis.

Frequency is measured in hertz.
It is the reciprocal of the period.

RMS provides an effective value for power calculations.
For a sine wave, RMS equals peak divided by square root of two.

Power factor indicates how effectively current is converted into useful power.
It equals cosine of the phase angle for sinusoidal systems.

Inductive loads draw current that lags voltage.
Motors and transformers commonly produce lagging power factor.

Capacitors supply leading reactive power.
They reduce the reactive current drawn from the source.

KVL follows conservation of energy in a circuit loop.
Voltage rises and drops balance around the loop.

Transformers change voltage and current levels without changing frequency ideally.
They require alternating magnetic flux.

The same current flows through series resistors.
Equivalent resistance equals the sum of individual resistances.

Induced voltage is proportional to the number of turns.
Current changes inversely in an ideal transformer.